I mostly ignore, and tend to be skeptical of, most pronouncements on foods that supposedly kill us and foods that are supposedly superfoods. I have a solid love of meat and have never let the fear of saturated fat stop me from enjoying a good steak from time to time.

Our distrust of saturated fat can be traced back to the 1950s, to a man named Ancel Benjamin Keys, a scientist at the University of Minnesota. Dr. Keys was formidably persuasive and, through sheer force of will, rose to the top of the nutrition world...

As the director of the largest nutrition study to date, Dr. Keys was in an excellent position to promote his idea. The "Seven Countries" study that he conducted on nearly 13,000 men in the U.S., Japan and Europe ostensibly demonstrated that heart disease wasn't the inevitable result of aging but could be linked to poor nutrition.

Critics have pointed out that Dr. Keys violated several basic scientific norms in his study. For one, he didn't choose countries randomly but instead selected only those likely to prove his beliefs, including Yugoslavia, Finland and Italy. Excluded were France, land of the famously healthy omelet eater, as well as other countries where people consumed a lot of fat yet didn't suffer from high rates of heart disease, such as Switzerland, Sweden and West Germany. The study's star subjects—upon whom much of our current understanding of the Mediterranean diet is based—were peasants from Crete, islanders who tilled their fields well into old age and who appeared to eat very little meat or cheese.

As it turns out, Dr. Keys visited Crete during an unrepresentative period of extreme hardship after World War II. Furthermore, he made the mistake of measuring the islanders' diet partly during Lent, when they were forgoing meat and cheese. Dr. Keys therefore undercounted their consumption of saturated fat. Also, due to problems with the surveys, he ended up relying on data from just a few dozen men—far from the representative sample of 655 that he had initially selected. These flaws weren't revealed until much later, in a 2002 paper by scientists investigating the work on Crete—but by then, the misimpression left by his erroneous data had become international dogma.

In 1961, Dr. Keys sealed saturated fat's fate by landing a position on the nutrition committee of the American Heart Association, whose dietary guidelines are considered the gold standard. Although the committee had originally been skeptical of his hypothesis, it issued, in that year, the country's first-ever guidelines targeting saturated fats. The U.S. Department of Agriculture followed in 1980.

Don't these guys know this is settled science? These saturated fat skeptics must be in the pay of big cattle.

The cherry-picking and small sample sizes are unfortunately a staple of science, but I particularly laughed at the practice of assessing meat consumption during Lent.